Randomised Controlled Clinical Trial of Intervention in Lifestyle and Therapeutic Adherence After Coronary Event Based on Interactive Web Application

Design

1. A randomized single-blind, parallel-group, controlled clinical trial performed on patients with coronary heart disease who underwent a percutaneous coronary intervention (PCI) with stent placement in the Cardiology Service of a public reference hospital complex providing specialist care in the province of Cadiz, Spain, in which 1500 coronary interventions procedures are performed per year.
2. Randomization and Blinding The randomization and allocation to each group (1:1, intervention and usual care) are based on computer-generated random numbers. The researchers responsible for the study do not participate in the allocation of the participants. Due to the kind of intervention, blinding is not possible when the participants are allocated to groups. To minimize any bias, objective clinical variables are measured in the evaluation visit and the analyses are performed by blinded researchers.
3. Study Sample The participants are eligible to participate if they have a confirmed diagnosis of coronary heart disease and undergo stenting with PCI. Furthermore, the participants must comply with the criteria explained in the section.
4. Sample Size To detect a medium effect size of Cohen's d of 0.5 regarding adherence to the Mediterranean diet (8.6 ± 2.0 puntos), food consumption, vegetables (471.4 g/day ± 230.0 g/day), fruit (308.4 g/day ± 188.6 g/day), meat and derived products (149.7 g/day ± 63.7 g/day), fish (122.3 g/day ± 73.5 g/day), physical activity (210.2 METs-min/day -metabolic equivalents- ±221.8 METs-min/day) and a 12% decrease in smoking habits (prevalence of 21% in pilot study), a 95% confidence interval and a power of 90%, the sample size is estimated at 100 patients in each group. Assuming a 20% loss to follow-up with 240 participants, 120 in each arm: intervention and usual care.
5. Recruitment After the PCI and during admission, the nurse will recruit eligible patients and their care partners, will ask them to sign the informed consent, perform the initial assessment and organize a programmed visit after 36 weeks. A card will be provided with the date of the appointment and a telephone number for any changes.

The participants allocated to the usual care group receive the standard prescribed care and advice about medication, and lifestyle.

Both groups will be provided with written recommendations and an explanation about the standard Mediterranean diet, physical activity, stopping smoking and treatment adherence.

Before hospital discharge, all the patients will be encouraged to follow a healthy lifestyle. Stages of change strategies will be used in addition to a motivational and behavior changing interview. Written information will be provided about risk factors, lifestyle goals, a suggested healthy menu, recommendations about the daily intake of food groups, and the other behavior that the intervention is targeting. 6. Intervention The intervention begins during the patient's stay in hospital immediately after a coronary event. The participants from the intervention group and their partner/carer will complete a short online tutorial describing the mobile application accessed using a mobile telephone or tablet. They will be advised to use the application for at least 15 min per day. This time has been considered sufficient for the daily recording of data in the pilot study. The intervention will last 36 weeks. If the patient does not record data for a week, he/she receives a message through the app encouraging him to use it. The patients may resolve any queries using the application's built-in messaging function, to which the nurse will reply through this messaging service or with a telephone call. This avoids many patient visits to the doctor for consultations and reduces human resource needs.